Hyper-V Replication and Failover

[Bison]

This may be a bit long. I have 2 networks on different subnets connected via IP Sec VPN's using our Fortigate Firewalls. Let's say one Network is 10.10.1.1/24 and the other network is 10.10.50.1/24. Replication works great (still working on the traffic shaping rules but seems to be good). So one of the servers I am replicating is our AD/DNS server which EVERYONE needs to communicate to of course (in case of a failover). My issue is, the servers are on the 10.10.1.1/24 network but replicating to the 10.10.50.1/24 Network. So once I fail them over they are unable to communicate outside so therefore nothing can communicate to them in case of a failover. I have tried a couple of things with the Fortigate like creating a VLAN for the 1.1 network but when I do that it takes down the VPN tunnel because it's the same subnet. The same thing happens when using the secondary IP address on the fortigate as well. Let's say that the main server is 10.10.1.15. So my question is, what would be best to way to get the 10.10.1.15 server to communicate out in case of fail over on the 10.10.50.1 subnet?